First my observation: Almost every day I sit in my boat at the marina and watch all the wind speed detectors (those little cup thingies) merrily and rapidly turning while at deck level the various wind generators on boats around me are either turning very slowly, or not at all.

My question that comes out of this observation is: Would it be possible to make a small trickle chargerwind generator out of the wind speed detector device? If so, where would I find a small generator to use? Or would you lose too much through resistance because of the long wiring run from the mast top?

YES, you can build a very small wind generator, and its simple.
Simple does not mean easy tho.

Any permanent magnet DC motor can be used to generate electricity. A small one, like from a remote control car or toy could be used. In Canada we have a store called Princess Auto where these can be purchased pretty cheap.

Next, you need some fan blades. Plastic window blinds work well.

Now just some way to mount the blades, and connect to the motor. Maybe playdoh?

Any voltage over 13 will charge a 12volt battery. The current will be so low that you won't need a voltage regulator.

However, its a lot of work for a little power, when, like another poster said, you could just buy a small solar panel. Still, would be a cool project. Maybe get your kids to build one for science fair.

Or a simple resistance test. Go up the mast and poke your finger between the spokes and see how much force is applied to your finger. Then go to one of the neighbours wind gens and repeat the experiment. Let us know how it works out. Some typos expected...

The cups spin because they have no resistance. Once you try to generate power, you create resistance and it stops/slows the spinning.

Exactly. First Law of Thermodynamics. Energy out cannot exceed energy in. The little wind cups are not trying to capture energy from the wind. They are just spinning freely (or almost so) and recording the speed at which they spin (which does require a little bit of energy, but not enough to matter). Try to capture a meaningful amount of energy from the wind and it requires a meaningful amount of wind energy to do it.